Since Congress can't compromise any more, we voters have to act at the polls.

That's what happened Tuesday in Mississippi when quiet, moderate incumbent Sen. Thad Cochran got an unusual assist from Democrats, including many black voters, to win his Republican primary. With those unlikely ballot-box allies, Cochran defeated tea party favorite State Sen. Chris McDaniel.

Afterward, an angry McDaniel claimed that Cochran had called in the troops of crossover primary voters and abandoned the conservative movement: "There is something a bit unusual about a Republican primary that's decided by liberal Democrats. ... So much for principles."

Never mind that McDaniel had relied on the money and support of outside groups.

For months, the contest between Cochran and McDaniel was viewed as this year's main event in the clash between ultra-conservatives and Republican incumbents. When Virginia's Rep. Eric Cantor, the House majority leader, was toppled in his primary recently, the Mississippi race really heated up.

As the New York Times put it: "Cochran shifted his campaign message from polishing his conservative credentials to extolling his record of keeping Mississippi flush with federal cash. He also attacked Mr. McDaniel for his vows of austerity, especially in education."

It worked, and the crossover votes from Democrats left many of McDaniel's supporters seething about a "corrupt" system.

It's not corrupt. It's called democracy. It's called voting the way you want to vote. And the top vote-getter wins -- no matter what combinations of support he or she receives.

In Mississippi, many blacks came out, voted and helped turn the tide. One analyst tweeted: "Turnout increased by 92 percent in Jefferson County, the county where black (voters) represent the largest share of eligible (voters) in the country."

No wonder the GOP-led Supreme Court wants to reverse black voting rights. But beware, the next thing we know the tea party will be trying to suppress the Republican vote, too.

As for the fairness question: Has it been fair that the nearly 700,000 residents of Tennessee's 3rd District have been served since 2010 by a representative who only received about 28 percent of the votes cast in his first Republican primary in 2010?

Chuck Fleischmann received only 26,860 votes of the 90,528 votes cast in the GOP primary election that year. In that same year's Democratic primary election, about 18,000 votes were cast. Later, in November 2010, Fleischmann won the general election in a very conservative district with only 57 percent of the 162,056 votes cast.

Two years later, he still didn't have overwhelming primary support from voters. In August 2012, Fleischmann received 29,947 votes -- 39 percent of the ballots cast.

Is is fair? No, it's not fair, but that's democracy. In a very red district in a very red state in a very red region, Democrats and moderates alike have too few options not to exercise a vote to elect the best leader possible. Sometimes that means picking the lesser of two evils -- or at least the lesser of two undesired choices.

Perhaps it would be better, certainly less noisy, if we just let all candidates run a few weeks before a general election and then have a run-off between the two top vote-getters in the top two parties.

But we don't do that. Instead, coalitions of moderate Republicans and liberal voters may have to continue to ensure that the primary elections offer us choices in general elections that will give us and our country the best chance at a true, functional government.